x402-gated API key endpoint on Base, paying $0.02 in USDC per request.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. It is one of many endpoints offered by the lowpaymentfee.com platform, which hosts a collection of pay-per-request APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per call settled in USDC on the Base network.
The specific resource at `/api/v1/apikeys/37` appears to be an API-key provisioning or access endpoint. The x402 challenge confirms it is live, accepting POST requests, and requires an exact payment of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals → $0.02) to the payee address 0x1A2B…85F3. The payment timeout is 300 seconds. No OpenAPI schema, detailed documentation, or example responses were found beyond the landing page; the docs, pricing, API, and README pages all rendered only a "Connect wallet" prompt with no substantive content.
The broader platform advertises no API keys required, no rate limits, and instant access for its other endpoints. However, the specific endpoint probed is labeled "Premium API Access" and sits under an `/apikeys/` path, suggesting it may issue or manage API keys. Without further documentation it is unclear exactly what payload to send or what the response contains.
Capabilities
Use cases
- —Programmatically purchasing or provisioning API keys via a single x402-paid POST request
- —Agents autonomously acquiring access credentials without traditional signup flows
- —Demonstrating x402 payment protocol integration for per-call billing
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs on Base
- —AI agents that need to autonomously acquire API keys via crypto micropayments
- —Projects wanting no-signup, pay-per-use API access
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Applications requiring free or subscription-based API key management
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/37 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation beyond a landing page, no example request/response payloads, and the docs/pricing/README pages are empty. The purpose of this specific endpoint is ambiguous.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown.
- —Docs, pricing, API, and README pages all render only 'Connect wallet' with no substantive content.
- —The exact purpose of /api/v1/apikeys/37 is unclear — it may provision keys or grant access, but no details are documented.
- —No terms of service, rate limit details, or SLA information found.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/apikeys/37
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/apikeys/37
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com